关键词:
Distribution characteristics of data;Fisher discrimination;kernel principal component analysis (KPCA);Powerformer;stator single-line-to-ground fault
摘要:
Some traditional protection schemes cannot detect the faulted Powerformer when a stator single line-to-ground fault occurs in parallel Powerformers. A new discrimination method based on kernel principal component analysis (KPCA) and Fisher discrimination analysis considering the distribution characteristics of the data is proposed in this paper. First, algorithms of KPCA and Fisher discrimination are introduced. In order to increase correct rate of the fault recognition, the kernel function for distribution characteristics of the data is selected according to error rate under historical fault data, which is different from the existing applying validation methods. Then, the detected data in system model is processed to detect whether stator single line-to-ground fault occurred in Powerformer by KPCA and Fisher discrimination analysis based on the optimal kernel function. Finally, simulation results show that the proposed scheme can exactly detect the fault for Powerformer in different neutral grounding systems when stator single line-to-ground fault occurred.
期刊:
Proceedings of the 5th IEEE International Conference on Electric Utility Deregulation, Restructuring and Power Technologies, DRPT 2015,2015年:1695-1699
会议论文集名称:
2015 5th International Conference on Electric Utility Deregulation and Restructuring and Power Technologies (DRPT)
关键词:
high-frequency excitation deicing;uniform transmission line theory;deicing power attenuation;finite element analysis
摘要:
Transmission line icing is a common natural disaster in southern China with great harm to the security operation of power systems. Deicing method with high-frequency excitation has the advantages of small ice-melting current and high ice-melting efficiency, but over high operating frequency and voltage would produce electromagnetic interference to the surrounding radio communication, cause corona loss to reduce the effect of melting ice, and may increase the cost of manufacture high-frequency excitation equipment. In this paper, uniform transmission line theory is used to determine the optimum operating frequency and voltage of the excitation source with considering the deicing power attenuation. The excitation deicing method with parameters 3kHz/11kV and deicing effect are identified, using MATLAB and ANSYS simulation to verify its feasibility and comparing the deicing effect with DC shorted deicing. The research result shows the superiority of deicing that it reduces ice-melting current and power capacity, and reduces the ice-melting time to improve deicing efficiency. The electromagnetic interference, corona loss, and the manufacturing cost of the excitation source are also reduced.
作者机构:
[李泽文; 舒磊; 邓丰; Zeng, Xiangjun; 邓拓夫] Hunan Province Key Laboratory of Smart Grids Operation and Control, Changsha University of Science and Technology, Changsha;410114, China;[李泽文; 舒磊; 邓丰; Zeng, Xiangjun; 邓拓夫] 410114, China
会议论文集名称:
Proceedings of 2015 International Conference on Power Electronics and Energy Engineering(PEEE 2015-1)
关键词:
VSC-HVDC;equivalent circuit;small signal stability;transmission capacity
摘要:
the external volt-ampere characteristic of the rectifier and inverter station of the VSC-HVDC (Voltage Sourced Converter-High Voltage Direct Current) system is simplified and the dc network equivalent circuit of VSC-HVDC system is built. The small signal model of the VSC-HVDC system is then derived. The transmission capacity is calculated under small-signal stability constraints and three influence factors are also obtained. Simulation is conducted by using PSCAD/EMTDC software. The simulation results demonstrate that the transmission capacity of VSC-HVDC system supply a passive network is be quite affected by the DC voltage, DC-side capacitance, and the resistance and reactance of the DC transmission lines.
作者:
Yang, Hongzhao;Qiu, Jing;Zhang, Sanhua;Lai, Mingyong;Dong, Zhao Yang
期刊:
International Journal of Emerging Electric Power Systems,2015年16(6):525-536 ISSN:2194-5756
通讯作者:
Yang, Hongzhao(yhm5218@hotmail.com)
作者机构:
[Yang, Hongzhao; Zhang, Sanhua; Lai, Mingyong] Hunan Provincial Engineering Research Center of Electric Transportation and Smart Distributed Network, Hunan Provincial Key Laboratory of Smart Grids Operation and Control, School of Economics and Management, Changsha University of Science and Technology, Changsha 410114, China;[Qiu, Jing] Centre for Intelligent Electricity Networks, The University of Newcastle, NSW 2308, Australia;[Dong, Zhao Yang] School of Electrical and Information Engineering, The University of Sydney, NSW 2006, Australia
通讯机构:
[Hongzhao Yang] H;Hunan Provincial Engineering Research Center of Electric Transportation and Smart Distributed Network, Hunan Provincial Key Laboratory of Smart Grids Operation and Control, School of Economics and Management, Changsha University of Science and Technology, Changsha 410114, China
关键词:
Electric industry;Gas industry;Gases;Natural gas;Natural gas pipelines;Petroleum prospecting;Power markets;Gas market;Impact analysis;Interdependency assessment;Investment decisions;National electricity markets;Natural gas exploration;Power transmission limit;Technological development;Investments
摘要:
Considering the increment of air-conditional electricity consumption, air-conditioning load aggregators (ALA) are prone to participate in bidding electricity market by managing enormous quantity and dispersive air-conditioning load (AL), which not only reduces load peak-valley difference, but also provides the opportunity for AL to take part in power market bidding. This work adopts reference price effect from behaviour economics to depict electricity consumption preference. A bi-level optimization method is being established. The upper level problem aims to maximize the social welfare, while the lower level aims to maximize the ALA benefits based on consumers' preference. Karush-Kuhn-Tucker condition is being applied to transfer the complex bi-level problem to a solvable sing-level problem. Case studies are provided to verify the feasibility of proposed model.
作者机构:
[张芳; Zeng X.] School of Electrical & Information Engineering, Changsha University of Science and Technology, Changsha, 410076, China;[毕大强] State Key Lab of Power System, Dept of Electrical Engineering, Tsinghua University, Beijing, 100084, China;[倪凤燕] 704th Research Institute, CSIC, Shanghai, 200031, China
通讯机构:
[Zhang, F.] S;School of Electrical & Information Engineering, Changsha University of Science and TechnologyChina
作者机构:
[毕大强] State Key Lab. of Power System, Dept. of Electrical Engineering, Tsinghua University, Beijing, 100084, China;[王思斯; 张芳] Xiangtan Power Supply Bureau, Xiangtan, 411104, China;[Zeng X.] Hunan Province Key Laboratory of Smart Grids Operation and Control, Changsha University of Science and Technology, Changsha, 410076, China
关键词:
船舶;直流区域配电系统;层次分析法;综合目标函数;整数规划
摘要:
船舶电力系统故障恢复过程是通过改变电网的供电路径来实现重要负载的连续供电,对提高船舶的生命力和供电可靠性具有重要意义.以负荷供电量最大和开关动作次数最小作为目标函数,建立一种用于船舶直流区域配电系统的多目标故障恢复模型.然后将不同量纲的目标函数进行单位化,再通过层次分析法(The analytic hierarchy process , AHP)把这些已单位化的函数进行综合.最后利用整数规划(Integer Programming, IP)方法,对综合目标函数进行优化求解,得到最优开关动作序列,最大程度的保证系统的供电连续性.一个典型的船舶直流区域配电系统的故障恢复仿真结果验证了所提方法的可行性和有效性,对直流配电网的研究具有一定的借鉴作用.